1. Field of the Invention
The present invention relates to a blow-by gas recirculating system for an internal combustion engine, and more particularly, a blow-by gas recirculating system for an internal combustion engine that increases the temperature of blow-by gas by supplying high-temperature compressed air discharged from a compressor to an oil pan or a rocker cover.
2. Description of Related Art
In general, an internal combustion engine used as a power source in a vehicle, and the like includes a cylinder that forms a combustion chamber having a predetermined volume, a piston that reciprocates in the combustion chamber, a crank mechanism that switches the reciprocal motion of the piston to a rotational motion, a rocker cover (alternatively, a cylinder head cover) mounted on the top of the cylinder, and an oil pan that is mounted on the bottom of the cylinder and accommodates lubrication oil, and the like.
In the internal combustion engine, fuel and air flow into the combustion chamber, and then a mixture of the fuel and the air is compressed and exploded, and as a result, the piston performs the reciprocal motion and the reciprocal motion of the piston is switched to the rotational motion through the crank mechanism to generate rotational power required to drive the vehicle.
Some of uncombusted gas leak to the rocker cover or the oil pan in a compression stroke and some of combustion gas leak to the rocker cover or the oil pan in an expansion stroke while the internal combustion engine operates. Blow-by gas that leaks as above degrades the lubrication oil stored in the oil pan or corrodes an inner part of the internal combustion engine.
When the blow-by gas which is hazardous to the internal combustion engine is discharged to the atmosphere, air pollution is caused. Therefore, a blow-by gas recirculating system that draws out the blow-by gas from the internal combustion engine, which is recirculated and recombusted is applied to the internal combustion engine.
A blow-by gas recirculating system in the related art primarily uses closed crankcase ventilation (hereinafter, referred to as CCV) or positive crankcase ventilation (PCV), and such a system includes a ventilation passage for connecting the rocker cover or the oil pan with an intake system of the internal combustion engine, for example, a surge tank, thereby guiding the blow-by gas, which leaks to the rocker cover or the oil pan, to the intake system of the internal combustion engine through the ventilation passage.
The CCV includes a housing that incorporates a filter separating oil contained the blow-by gas, an inflow port that allows the blow-by gas, which leaks to a crankcase of the internal combustion engine, to flow into the housing, an exhaust port that allows the blow-by gas, which flows in through the inflow port, to be exhausted to the intake system of the internal combustion engine after oil is filtered through the filter, a drain port that allows the oil filtered through the filter to be drained to the oil pan, and the like.
However, when a vehicle adopting the blow-by gas recirculating system including the CCV in the related art is operated in a very cold weather place, a freezing phenomenon or slush is generated due to moisture contained in the blow-by gas, and the like by a lowoutdoor air temperature, and as a result, the blow-by gas may not be smoothly recirculated.
In order to reduce a concern about the occurrence of the freezing phenomenon or the slush, in some cases, the length of the blow-by gas passage is decreased, the diameter of the passage is increased, or an insulating material is used, but the methods are not effective.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.